/Engine/Source/Runtime/GeometryCore/Public/DynamicMesh/MeshTangents.h
Return tangent and bitangent at a vertex of triangle for per-triangle computed tangents
template<typename VectorType, typename OtherRealType> void GetPerTriangleTangent ( int32 TriangleID, int32 TriVertIdx, VectorType & TangentOut, VectorType & BitangentOut ) const